Add X11 Render window stub
Add name property to mesh class
Fix Linux compilation errors in Attachable class
Remove AssImp dependency

Wrote own obj loader.
Remove source file for abstract base class RenderContext
Add input system stub
Fix some friend declaration keywords
Disable editor build

Enable after Qt backend implementation is done.
Rename RenderWindow factory method
Provide window handle from render window interface
Separate platform-dependent code
Add swap buffers method to render context
Create/destroy X11 window on show/hide
Add Lua 5.2 CMake config script

Lua 5.2 find script is not included in all distributions.
Fix event submodule compilation
Simplify game state addition
Whitespace fixes
Fix OBJ loading
Set projection matrix manually

Fixes rendering
Implement input and event systems for X11